From the Nodes section of OpsCenter, select different views (Ring or List) of the nodes that comprise a DataStax Enterprise
cluster and perform node management. View the status of agents, install and upgrade agents, and troubleshoot any agent
issues in the Agents view.

Use OpsCenter to run operations on nodes in an easy to use, visual way that takes the guesswork out of properly managing
nodes in a cluster.

Node management operations

Use OpsCenter to run operations on nodes in an easy to use, visual way that takes the
guesswork out of properly managing nodes in a cluster.

Managing multiple nodes

Use OpsCenter to run operations (or actions) on nodes in an easy to use, visual way that
takes the guesswork out of properly managing nodes in a cluster. Most node management
operations can be run on multiple nodes of your choosing (for example, all the nodes in a
cluster, all the nodes in a single datacenter, or a handful of problem nodes). The
operations run in a rolling fashion and do not continue on to the next node until the
previous one has completed successfully. If the operation fails on a node, the entire
process stops.

To run an operation on multiple nodes, select those nodes in List View and choose an
appropriate action.

Notifications appear when an operation starts and completes. Clicking Show
Details takes you to the Activities section.

Managing single nodes

To run an operation on a single node, click that node from Ring View or List View and choose an action from
the Actions menu from the node details view:

Operations details

View Metrics (single node only)

Redirects you to the Dashboard area of OpsCenter where you can select metrics graphs
and configure performance views for the selected node.

View Replication (ring view, single datacenter only)

Shows the replication relationships between the selected node and other nodes in the
cluster, based on the selected keyspace.

Start/Stop

Starts or stops the DataStax Enterprise process on the node.

Restart

Restarts the DataStax Enterprise process on the node. If running on multiple nodes,
each node is started as soon as the start command for the previous node returns. If you
want the operation to wait for thrift to be active on each node before continuing, use
the Rolling Restart action.

Cleanup

Removes rows for which the node is no longer responsible. This is usually done after
changing the partitioner tokens or the replication options for a cluster.

Compact

Performs a major compaction, which is not a recommended procedure in most DataStax
Enterprise clusters.

Flush

Flushes to disk as persistent SSTables the recent writes currently stored in memory
(memtables).

Repair

Makes a node consistent with its replicas by doing an in-memory comparison of all the
rows of a table and resolving any discrepancies between replicas by updating outdated
rows with the current data.

Perform GC

Forces the Java Virtual Machine (JVM) on the selected node to perform a garbage
collection (GC).

Decommission (single node only)

Removes a node from the cluster and streams its data to neighboring replicas.

Drain (single node only)

Causes the recent writes currently stored in memory (memtables) to be flushed to disk
as persistent SSTables and then makes the node read-only. The node stops accepting new
writes. Draining a node is usually done when upgrading a node.

Move (single node only)

Changes the partitioner token assignment for the node, thus changing the range of data
that the node is responsible for. Not enabled if vnodes are enabled.

From the Nodes section of OpsCenter, select different views (Ring or List) of the nodes that comprise a DataStax Enterprise
cluster and perform node management. View the status of agents, install and upgrade agents, and troubleshoot any agent
issues in the Agents view.

OpsCenter manages multiple DataStax Enterprise clusters with a single install of the central opscenterd server. Administer
your clusters using the options available from the Cluster Actions menu. Generate reports from the Help menu.

Monitor performance metrics in the OpsCenter Dashboard. Real-time and historical performance metrics are available at
different granularities: cluster-wide, per node, per table (column family), or storage tier.

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